The Xiris Blog

If you use slip rings and rotating torches in cladding, there now is a way that you can see the welding process much more clearly than ever before.

Xiris has successfully tested our XVC-1000 and XVC-1000e weld cameras on rotating welding machines using slip rings—and the cameras work perfectly! Unlike other cameras with electrical noise interferences, the Xiris Weld Cameras are not affected by the electrical noise and interferences common with running video over a slip ring.

Slip rings are electromechanical devices that are designed to pass electrical signals from a rotary source (such as a weld camera mounted next to one or more torches that rotate around the inside of a part) to a stationary receiver (such as a computer which receives the video data from the cameras). They are devices that allow for the transmission of an electrical signal and power. By employing a metal brush that rubs against a rotating metal ring, the video signal coming from the camera travels through the connection, avoiding the use of solid cables that could potentially twist indefinitely until damaged.

Weld cameras are making their way into a variety of cladding operations. However, it is very difficult to monitor cladding on the inside of the pipe, especially when the pipe stays stationary and the torch rotates. This can be a problem for a standard connection: as the torch rotates continuously, cables cannot withstand very many rotations before they break. Therefore, the use of slip rings would be a natural solution. However, slip rings typically are used for motor signals and power, applications that are a little more tolerant of electrical noise than video signals. Typical industrial cameras haven’t worked well with slip rings because their analog signals are not resistant to electrical noise.

The problem is that cladding is typically done using a TIG welding process, which is notorious for generating lots of electrical noise that can kill standard electronics due to its high-frequency starts.

But the Xiris weld cameras don’t die or short-circuit from high-frequency welding noise, even with a slip ring. Our cameras and the welding machine keep working together when used with a slip ring—allowing operators to remotely see high dynamic range (HDR) images of their cladding process, in real time, on a computer screen, remotely. The Xiris weld cameras with HDR capability permit operators to see both the super-bright weld arc and its dark surrounding background, with no need to stop the process.

We’ve tested our HDR weld cameras on slip-ring applications numerous times, and the advanced electronics in the cameras have repeatedly been up to the task. We’d be glad to demonstrate on your set-up.

This is new technology, but it’s ready now to improve the efficiency of your rotating-torch cladding.

Cladding material on to the inside surface of a pipe requires movement of the torch head relative to the pipe surface. This is done by either rotating the pipe, keeping the welding torch stationary, or by rotating the welding torch and keeping the pipe stationary. For longer sections of pipe, or for pipe that has already had a number of sections welded together, moving the pipe itself is not always practical. Instead, the weld torch must be rotated to perform the cladding operation.

To remotely monitor the cladding process, a weld camera can be mounted next to the weld torch, allowing operators to detect defects in the cladding process while they are happening and respond immediately with positional adjustments or even by tweaking the material inputs to the optimize the clad. While it is not too difficult when the torch remains stationary, it is more of a challenge when the torch has to rotate through many rotations to complete the cladding operation.

To solve this problem, the Xiris XVC-1000 and XVC-1000e weld cameras were integrated and successfully tested on a slip ring to transmit the power and electrical signals from the camera inside the pipe to an external computer. A slip ring is an electromechanical device that allows the transmission of power and electrical signals from a stationary device such as the external computer to a rotating device – the weld camera inside the pipe.

With the successful testing of the video transmission by slip ring, it is now possible to equip cladding machines that have rotating torches or carriages with a weld camera. This provides much better process monitoring in ways that were not possible previously as operators were forced to watch the cladding through a welding shield or helmet, trying to follow the arc around in circles as best as they could.

Recent advancements in machine vision technology have made a new type of inspection able to see defects related to the forming and welding area of a tube or pipe. The result is improved quality assurance and process control on the production line. The new type of inspection device is a laser-based triangulation system that measures the outside contour of a tube or pipe in the vicinity of its weld.

Typically NDT systems are placed at the end of a production as a final check. However, the laser inspection system can be placed directly after the weld box. This system can let operators know what is changing in their welding process, allowing them to perform corrective action before significant scrap occurs. This capacity is especially helpful for one of the most common defects found across all types of Tube manufacturing: Tube Scarf defects.

The Scarfing Width

In certain situations on ERW/HF tube and pipe production lines, there is not enough space to perform the Non Destructive Inspection (NDI) measurements right after the weld box because the scarf tool (used to remove excessive bead from the tube) is placed directly after the weld box. In such situations, the measurement process must be made after the scarfing tool, measuring the flat area of the tube where the scarf has occurred. On some production lines, this measurement is essential to identify the shape and profile of the tube, and to understand how it is travelling through its forming process.

Known as the scarf width, this measurement is defined as the length of the “flat” portion of the tube that appears after the weld bead has been removed by scarfing. Scarf width measurement changes quickly during production, so it is best averaged over a number of inspections in order to make the measurement stable.

The Scarf Width, where “w” = the width of the defect.

How the WI2000p System Measures the Scarf Width

Xiris Automation Inc. has developed a non-destructive inspection system called the WI2000p Weld Inspection System. The WI2000p includes a laser line and a camera whose optical axis is offset to the axis of the laser line by an “offset angle”. The WI2000p creates a visible cross-section of the tube by projecting the laser line on to the tube and capturing an image of the line using the camera. The resulting image shows a profile of the tube surface as if it were cut in cross section. If a tube is ideally round, the laser image will represent a section of an ellipse and any anomaly such as a freeze line defect can be mathematically detected.

The WI2000p bases all of its measurements on the differences between the actual laser profile line seen by the camera, and the ideal mathematical profile based on the tube parameters. By knowing the position of the actual laser profile, the ideal profile, and the size of the pixels in the image, the WI2000p can detect weld bead profile defects that often escape detection by other quality tools such as Eddy Current testing, or Ultrasonic Testing techniques

Conclusion

Overall, laser-based 3D imaging systems, such as the WI2000p from Xiris, offer an excellent measurement option for tube mill owners/operators who want additional, real-time monitoring of weld features. They can be used in a proactive manner, warning operators what is changing in their welding process so that they can perform corrective action before significant scrap occurs And by measuring the outside contour of a weld, laser-based 3D imaging systems can operate on any type of material, regardless of its reflectance or magnetic properties, using a single head to perform the measurement.

Recent advancements in machine vision technology have made a new type of inspection able to see defects related to the forming and welding area of a tube or pipe. The result is improved quality assurance and process control on the production line. The new type of inspection device is a laser-based triangulation system that measures the outside contour of a tube or pipe in the vicinity of its weld.

Typically NDT systems are placed at the end of a production as a final check. However, the laser inspection system can be placed directly after the weld box. This system can let operators know what is changing in their welding process, allowing them to perform corrective action before significant scrap occurs. This capacity is especially helpful for one of the most common defects found across ERW Tube manufacturing: Freeze Line defects in the weld bead.

The Freeze Line Defect

Particularly in Electric Resistance Welding (ERW) or High Frequency (HF) welding processes, incomplete heating of the faces of the parent material can sometimes occur, resulting in a potentially cold-welded joint, which manifests itself as a line or seam extending from the top surface of a weld down into the welded area, in the shape of a sharp valley. Such a defect could indicate major metallurgical or structural problems in a weld, such as cold welding or improper forming. It can very often be a point of a major failure of a weld in high-stress applications because the freeze line acts as a crack initiator into the welded material. The Freeze Line becomes a concern to weld operators when it goes below the surface of the parent material of the tube because once the weld bead has been removed through grinding or scarfing, there is a risk that a void of non-welded material could be left behind.

The freeze line is measured from the lowest point of any contour in the weld bead to the surface of the parent material as defined by the ideal circle scribed by the walls of material beyond the weld zone. If the freeze line goes below a pre-defined height, then it is considered a defect.

The Freeze Line Defect, where “h” = the height of the defect.

How the WI2000p System Measures the Freeze Line Defect

Xiris Automation Inc. has developed a non-destructive inspection system called the WI2000p Weld Inspection System. The WI2000p includes a laser line and a camera whose optical axis is offset to the axis of the laser line by an “offset angle”. The WI2000p creates a visible cross-section of the tube by projecting the laser line on to the tube and capturing an image of the line using the camera. The resulting image shows a profile of the tube surface as if it were cut in cross section. If a tube is ideally round, the laser image will represent a section of an ellipse and any anomaly such as a freeze line defect can be mathematically detected.

The WI2000p bases all of its measurements on the differences between the actual laser profile line seen by the camera, and the ideal mathematical profile based on the tube parameters. By knowing the position of the actual laser profile, the ideal profile, and the size of the pixels in the image, the WI2000p can detect weld bead profile defects that often escape detection by other quality tools such as Eddy Current testing, or Ultrasonic Testing techniques

Conclusion

Overall, laser-based 3D imaging systems, such as the WI2000p from Xiris, offer an excellent measurement option for tube mill owners/operators who want additional, real-time monitoring of weld features. They can be used in a proactive manner, warning operators what is changing in their welding process so that they can perform corrective action before significant scrap occurs And by measuring the outside contour of a weld, laser-based 3D imaging systems can operate on any type of material, regardless of its reflectance or magnetic properties, using a single head to perform the measurement.

Recent advancements in machine vision technology have made a new type of inspection able to see defects related to the forming and welding area of a tube or pipe. The result is improved quality assurance and process control on the production line. The new type of inspection device is a laser-based triangulation system that measures the outside contour of a tube or pipe in the vicinity of its weld.

Typically NDT systems are placed at the end of a production as a final check. However, the laser inspection system can be placed directly after the weld box. This system can let operators know what is changing in their welding process, allowing them to perform corrective action before significant scrap occurs. This capacity is especially helpful for one of the most common defects found across all types of Tube manufacturing: excessive Bead Roll.

The Bead Roll Measurement

The nature of some welding processes such as Laser Beam Welding (LBW) or GTAW (TIG) require that the weld bead remains within narrow range around the centerline of the tube to ensure the best quality weld. Any small deviation from the centerline can cause a variety of welding defects mentioned earlier in this blog. With such precision welding processes, the bead position cannot change even momentarily or a bad weld will result. Bead roll could indicate setup problems in a mill where there are uneven forces on the tube that causes a gradual twisting. Often, this is avoided by placing the weld box as close as possible to the forming rollers. However, if a roll still exists in the tube beyond the weld box, the tube may be later rejected as downstream processes will not be able to process a twisted tube properly. In extreme cases, it could cause problems with bead removal later down the mill.

The Bead Roll angle is measured based on the midpoint between the left edge and right edge of the bead width. The difference between the midpoint position and a vertical axis through the center of the tube defines the angle of the bead roll. The actual angle also relies on using the ideal diameter of the parent material for calculation.

The Bead Roll Measurement, where “θ” = the measured angle.

How the WI2000p System Measures the Bead Roll

Xiris Automation Inc. has developed a non-destructive inspection system called the WI2000p Weld Inspection System. The WI2000p includes a laser line and a camera whose optical axis is offset to the axis of the laser line by an “offset angle”. The WI2000p creates a visible cross-section of the tube by projecting the laser line on to the tube and capturing an image of the line using the camera. The resulting image shows a profile of the tube surface as if it were cut in cross section. If a tube is ideally round, the laser image will represent a section of an ellipse and any anomaly such as a bead roll can be mathematically detected.

The WI2000p bases all of its measurements on the differences between the actual laser profile line seen by the camera, and the ideal mathematical profile based on the tube parameters. By knowing the position of the actual laser profile, the ideal profile, and the size of the pixels in the image, the WI2000p can detect subtle bead rolling that often escape detection by other quality tools such as Eddy Current testing, or Ultrasonic Testing techniques.

Conclusion

A new technique for detecting bead roll on welded Tube and Pipe has been developed by Xiris and is known as the WI2000p weld inspection system. The WI2000p system is a laser based inspection system that is capable of detecting bead roll immediately after welding to alert the operator of a defect in time to minimize rejects. The result is improved quality, fewer field defects and a more reliable method for the operator to optimize the welding process.

Recent advancements in machine vision technology have made a new type of inspection able to see defects related to the forming and welding area of a tube or pipe. The result is improved quality assurance and process control on the production line. The new type of inspection device is a laser-based triangulation system that measures the outside contour of a tube or pipe in the vicinity of its weld.

Typically NDT systems are placed at the end of a production as a final check. However, the laser inspection system can be placed directly after the weld box. This system can let operators know what is changing in their welding process, allowing them to perform corrective action before significant scrap occurs. This capacity is especially helpful for one of the most common defects found across all types of Tube manufacturing: Tube Forming Defects, otherwise known as Deflection.

The Deflection Defect

Defection is defined as the overall variance of the tube parent material from an ideal circle. This defect moves the starting point of all other defects that the Xiris WI2000p measures, up or down. The deflection measurement detects the overall deflection from the ideal circle to the closest tube side within the bead area. The deflection metric is determined by measuring the distance between the sections of the parent material outside of the weld bead width and the ideal profile line. The deflection usually represents the overall offset of the tube walls before welding and is indicative of forming set up or variances in the parent material’s metallurgy.

The drawing below illustrates the defect:

The Defection Defect, where “h” = the height of the defect.

How the WI2000p System Measures the Deflection Defect

Xiris Automation Inc. has developed a non-destructive inspection system called the WI2000p Weld Inspection System. The WI2000p includes a laser line and a camera whose optical axis is offset to the axis of the laser line by an “offset angle”. The WI2000p creates a visible cross-section of the tube by projecting the laser line on to the tube and capturing an image of the line using the camera. The resulting image shows a profile of the tube surface as if it were cut in cross section. If a tube is ideally round, the laser image will represent a section of an ellipse and any anomaly such as a tube deflection can be mathematically detected.

The WI2000p bases all of its measurements on the differences between the actual laser profile line seen by the camera, and the ideal mathematical profile based on the tube parameters. By knowing the position of the actual laser profile, the ideal profile, and the size of the pixels in the image, the WI2000p can detect Deflection profile defects that often escape detection by other quality tools such as Eddy Current testing, or Ultrasonic Testing techniques

Conclusion

A new technique for detecting Deflection on welded Tube and Pipe has been developed by Xiris and is known as the WI2000p weld inspection system. The WI2000p system is a laser based inspection system that is capable of detecting Deflection defects immediately after welding to alert the operator of a defect in time to minimize rejects. The result is improved quality, fewer field defects and a more reliable method for the operator to optimize the welding process.

More source and videos of tube and pipe weld monitoring available at our online library!